1. Field of the Invention
The present invention relates generally to the heat insulator support in a manifold reactor and more particularly to such a support having a grommet of simple structure which can effectively hold the heat insulator and prevent it from being pulverized and discharged into the atmosphere.
2. Description of the Prior Art
Usually, in a manifold reactor, a re-combustion chamber is padded externally with a heat insulator for affording better preservation of heat. A common material from which the insulator is formed is a fibrous substance, such as a ceramic fiber, which, upon direct exposure to engine vibration or leaking gas, is liable to turn into dust and fly out or be discharged. A continuous portion of the heat insulator having uniform thickness is less liable to turn into dust and fly out, but a cut edge of the same is highly likely to do so. Particularly at the inlet port and its vicinity, where gaps are numerous between a port liner and a slide collar thereof, and between the outer core and the slide collar, pulverized heat insulator dust is liable to slip into such gaps, thereby jamming the slide collar, or to invade deeper into the re-combustion chamber and finally go out into the atmosphere through the outlet port.
A grommet capping the edge of the heat insulator around the inlet port will be useful for preventing the flying off of such dust.
In one conventional method, the heat insulator is held by a protector, which is welded to the reactor casing wall, but this method is not completely satisfactory since a cast casing has to be fabricated of a weldable expensive material and the welding requires high skill, resulting in a high cost of production.